title: Determination of arsenic in scalp hair samples from exposed subjects using microwave-assisted digestion with and without enrichment based on cloud point extraction by electrothermal atomic absorption spectrometry.
abstract: A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of trace quantities of arsenic (As) in scalp hair samples. The samples were subjected to microwave-assisted digestion in a mixture of nitric acid and hydrogen peroxide (2 + 1, v/v) prior to preconcentration by CPE. The As in digested samples was complexed with ammonium pyrrolidine dithiocarbamate (APDC), and the resultant As-PDC complex was extracted by a nonionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). After centrifugation, the surfactant-rich phase was diluted with 0.1 M HNO3 in methanol and analyzed by electrothermal atomic absorption spectrometry. The experimental parameters, i.e., amount of APDC, concentration of Triton X-114, equilibrium temperature and time, were optimized. For validation of the proposed method, a certified reference material (CRM) of human hair (BCR 397) was used. No significant difference (P > 0.05) was observed between the experimental results and certified values of the CRM (paired t-test). The LOD and LOQ obtained under the optimal conditions were 0.025 and 0.083 microg/kg, respectively. The developed method was applied for the determination of As in scalp hair samples from male and female subjects of two villages of Khairpur Mir's, Pakistan.
authors.affiliation: University of Sindh Jamshoro, Centre of Excellence in Analytical Chemistry, Pakistan. tgkazi@yahoo.com
authors.forename: Tasneem Gul
authors.initials: TG
authors.lastname: Kazi
authors.forename: Jameel Ahmad
authors.initials: JA
authors.lastname: Baig
authors.forename: Abdul Qadir
authors.initials: AQ
authors.lastname: Shah
authors.forename: Ghulam Abbas
authors.initials: GA
authors.lastname: Kandhro
authors.forename: Sumaira
authors.initials: S
authors.lastname: Khan
authors.forename: Hassan Imran
authors.initials: HI
authors.lastname: Afridi
authors.forename: Nida Fatima
authors.initials: NF
authors.lastname: Kolachi
authors.forename: Sham Kumar
authors.initials: SK
authors.lastname: Wadhwa
authors.forename: Faheem
authors.initials: F
authors.lastname: Shah
authors.forename: Akhtar Mehmood
authors.initials: AM
authors.lastname: Baig
mesh_terms: D000328:Adult; D000368:Aged; D001151:Arsenic / Q000032:analysis* / Q000633:toxicity; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008872:Microwaves; D008875:Middle Aged; D017830:Octoxynol; D010154:Pakistan; D011092:Polyethylene Glycols; D011759:Pyrrolidines; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013859:Thiocarbamates
chemical_list: D004785:Environmental Pollutants; D011759:Pyrrolidines; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D001151:Arsenic